How to resolve dependency conflicts

[xming521]

I have a project with two main features, but the libraries required by these two features have version conflicts. Both features are frequently used. Can I use Dependency groups to create separate environments for these two features?

[dimbleby]

no

[xming521]

So, do I have to create a new project or unify the dependencies of the two features?

[Meyyappan-AL]

You don't necessarily have to create a completely new repository, but since a single Python environment cannot hold conflicting package versions, you have two practical paths:

1. Unify the dependencies (If running in one environment):
   Try relaxing or adjusting the version bounds in pyproject.toml (or updating/downgrading the conflicting libraries) so both features can share a single, compatible set of dependencies.

2. Separate into sub-projects / workspace (If dependencies cannot be unified):
   If the version conflict is impossible to resolve, you must split the features into separate projects (or sub-packages within a monorepo). Each sub-project will have its own pyproject.toml and run in its own virtual environment or container.

[Meyyappan-AL]

No, dependency groups cannot be used to run conflicting library versions in the same project, because Poetry uses a single shared environment for the whole project.

Here are two simple ways to solve this:

1. Separate into two projects (Recommended)

If the features need completely different, conflicting library versions, split them into two separate sub-projects or repositories. Each project will have its own pyproject.toml and separate environment.

---

2. Use Optional Extras

If you want to keep everything in one codebase and users only need one feature at a time, define them as optional extras in pyproject.toml:

[tool.poetry.dependencies]
python = "^3.10"
package-a = { version = "^1.0", optional = true }
package-b = { version = "^2.0", optional = true }

[tool.poetry.extras]
feature-a = ["package-a"]
feature-b = ["package-b"]

How to use it:
Install only Feature A:

poetry install --extras "feature-a

Install only Feature B:

poetry install --extras "feature-b

Important Note for your answer
Because package-a and package-b have version conflicts, users can only install one extra at a time in a given environment. They cannot run poetry install --all-extras or install both extras together, because Poetry's single virtual environment cannot hold both conflicting packages at once.